Mining machine having independent means to rotate and oscillate cutters



March 21, 1967 E. M. ARENTZEN MINING MACHINE HAVING INDEPENDENT MEANS TO ROTATE AND OSCILLATE CUTTERS Filed March 8, 1965 //V l/E/V TOR.

El/VAA M. ARE/V TZEN I A f rorneys United States Patent f 3,310,347 MINING MACHINE HAVING INDEPENDENT MEANS T0 ROTATE AND OSCILLATE CUTTERS Einar M. Arentzen, Charleroi, Pa., assiguor to Lee-Norse Company, Charleroi, Pa., a corporation of Delaware Filed Mar. 8, 1965. Ser. No. 437,824 3 Claims. (Cl. 299-71) This invention is for a mining machine for the underground mining of coal and other minerals. It is an improvement in the machine disclosed in my prior Patent No. 2,695,164, granted Nov. 23, 1954, and my copending application Ser. No. 387,583, filed Aug. 5, 1964, and is also for an improvement in the invention disclosed in a copending application of even date herewith, Ser. No. 437,825, filed Mar. 8, 1965.

Machines of the type to which the present invention relates have a mobile chassis mounted on crawlers. There is a boom structure at the front of the machine which is pivoted at the front of the chassis for movement in a vertical arc, and which extends across substantially the full width of the machine. This boom has two arms mounted thereon, one at each side of the longitudinal center, and which are pivoted to swing toward and away from each other. Each has a cutter head at its outer end, each with cutter wheels that are rotated in vertical planes. A drive shaft extends lengthwise of each arm which is connected at its inner end through a universal joint to a driving motor, each cutter head having its own driving motor.

My patent above referred to discloses a link mechanism operated by eccentrics driven through the aforesaid drive shafts on the arms and connected to the boom for oscillating the arms. While this is a satisfactory arrangement, there is no provision for absorbing the shock when the cutter heads suddenly strike especially hard formations or rock inclusions in the coal. In the first of my aforesaid applications, fluid pressure cylinder and piston means is provided for oscillating the arms, but with very heavy machines the arms approach the limits of their travel at a relatively high speed, resulting in an abrupt stopping of the arms which it is difficult to cushion. In the other copending application there is shown a drive for oscillating the arms using fluid pressure motor means, and while this is a highly satisfactory arrangement for especially high powered large capacity machines, it is unnecessary and expensive for very light machines.

This application is for a mechanism especially useful in machines of smaller output capacity and for use in operations that do not permit or justify the use of this larger and more expensive drive for moving the arms.

According to the present invention, provision is made for oscillating the arms in opposite directions and in unison by an eccentric mechanism driven through an electric torque motor, so that if an overload is encountered, the motor may stall, butthe cutter wheels, being separately driven, can continue to operate to cut away the hard inclusion. This arrangement is relatively compact, light and inexpensive, making the use of the machine practical in smaller mines, low coal and other operations where a heavy duty machine is not required.

My invention may be more fully understood by reference to the accompanying drawings, in which:

FIG. 1 is a plan view of the forward end of a mining machine embodying my invention, part of the drive mechanism being shown in section, and the cutter wheels being only schematically illustrated; and

FIG. 2 is a side elevation of the portion of the machine shown in FIG. 1 in which the cutter wheels are also only schematically shown.

In the drawings, 2 designates the forward end of the machine body or chassis similar to that shown in my said patent or the copending applications.

3,313,347 Patented Mar. 21, 1967 There is a downwardly-sloping gathering apron 3 with gathering arms 4 thereon.

There is a boom 5 pivoted to the chassis at 6, and which may be swung up and down by hydraulic cylinder and piston units 7, one at each side of a central conveyor pan. The boom has a covered deck 8. There are two arms 9 extending forwardly under the deck with cutter heads 10 at the projecting forward ends. One arm is at each side of the longitudinal center line of the boom. Each cutter head has a pair of cutter wheels 11 thereon. The rear ends of the arms are swiveled for universal movement in gear housings 12 at their rear ends.

At each side of the chassis there is an electric motor 13 driving a shaft 14 that extends into the gear box 12 which is positioned forwardly of the motor. There is a universal joint in this box at the end of a drive shaft (not shown) extending lengthwise of the arm terminating at the gear box. This shaft drives the cutter wheels through gearing (not shown) in the cutter head.

The present invention is concerned with the mechanism for oscillating the arms back and forth sideways on the boom. This mechanism comprises an electric motor 20 at the center of the forward end of the boom with its shaft extending fore-and-aft on approximately the center line of the boom. A gear 21 on the motor shaft drives a shaft 22 through speed-reducing gears 23. This shaft extends forwardly from an enclosure or gear box 24. In this box there is journaled a vertical shaft 25 with a worm gear wheel 25a thereon (indicated by a dot-and-dash circle in the drawing, since it is above the level of the section through shaft 25).

The shaft 22 has a worm screw at 22a thereon that meshes with this gear, the general arrangement being similar to that shown in my copending application filed concurrently with this application.

There are two eccentric crank disks 26 and 27 keyed to the vertical shaft, one being below the other, and they are out of phase with each other, and both are at a level below the shaft 22 and the gear which it drives. Each eccentric rotates within an encircling collar, made in two parts bolted together, one part of each collar being affixed to or integral with a link. The collar on the upper disk 26 is designated 28 and its link is 29. The collar on the lower disk is designated 30, and its link is 31. As viewed in FIG. 1, the link 29 has its outer end pivotally connected at 32 with the lower arm 9 of the drawing at a point intermediate its ends. The other end of link 31 is similarly pivotally connected at 33 to the other arm.

When the motor 20 is operated, the shaft 25 is rotated to rotate the two eccentric disks. This causes the two links 29 and 31 to move toward and away from each other in unison, oscillating the cutter arms 9 at equal speeds and in opposite directions so that they move the cutter heads back and forth from the closed position shown in FIG. 1 to the dotted line position, and then together. Neither arm can move past a position where its cutter wheels interfere with or overlap the plane of the other.

With this arrangement the motors 13 can rotate their respective cutter wheels without the motor 21) being in operation or the arms may be oscillated without the motor 20 being driven, or either motor 13 may rotate its cutter Wheel without the arms being oscillated or with them in oscillation. These various conditions may at times be desirable in maneuvering the machine from one position or location in a mine to another.

This arrangement is especially desirable in machines for mining low coal, since as seen in FIG. 2, the height of the machine at the inner end of the boom with the boom lowered is very little more than is required for the apron and conveyor. This is made possible by locating the motor 26 at the forward end of the boom Where it is clear of coal being gathered into the apron or to the conveyor, 40, and is above the path of movement of the gathering arms. The motor 2G for relatively low-powered machines is small enough to be located in this position between the arms, and it does not extend above the tops of the cutter wheels so that it is always clear of the mine roof, an ddoes not extend below the cutter wheels, so that it is always above the mine floor.

While I have shown and described one embodiment of my invention, it will be understood that various changes and modifications may be made therein.

I claim:

1. In a mining machine of the class described having a supporting chassis and a boom at the front of the chassis arranged to be swung up and down in a vertical arc, the boom having a pair of cutter arms thereon which may be swung back and forth across the boom, one arm being at each side of the longitudinal center of the boom, each arm having a cutter head at the outer end thereof extending beyond the boom, and cutter wheels on each cutter head rotatable by power means, the invention comprising a mechanism for simultaneously moving the cutter arms toward and away from each other and the longitudinal center line of the boom, said mechanism comprising:

a shaft supported on the boom between the two arms and intermediate the ends of the boom,

an eccentric arm-operating means on the shaft,

a pair of links each having one end operatively engaging said eccentric means, one link of said pair extending laterally toward one cutter arm and the other link extending laterally toward the other cutter arm,

the other ends of said links being pivotally connected to the respective cutter arms toward which they extend at a point intermediate the ends of the arms,

and a horizontally-positioned electric motor mounted on the boom operatively connected with said shaft for rotating it, said motor having its top below the level of the top of the cutter wheels and its bottom above the bottom of said cutter wheels, said motor being operative independently of the power means for rotating the cutter wheels and vice versa.

2. A mining machine as defined in claim 1 wherein the electric motor is positioned on the longitudinal center line of the boom between said shaft and the forward end of the boom.

3. A mining machine as defined in claim 1 wherein the electric motor is positioned on the longitudinal center line of the boom between said shaft and the forward end of the boom, the shaft being vertical and the motor having a drive shaft which is horizontal, and gearing through which power is transmitted from the motor shaft to said vertical shaft.

References Cited by the Examiner UNITED STATES PATENTS 2,695,164 11/1954 Arentzen 29971 3,052,454 9/1962 Sibley 299-71 3,157,437 11/ 1964 Gonski 29971 3,170,732 2/1965 Hlinsky 29964 X ERNEST R. PURSER, Primary Examiner. 

1. IN A MINING MACHINE OF THE CLASS DESCRIBED HAVING A SUPPORTING CHASSIS AND A BOOM AT THE FRONT OF THE CHASSIS ARRANGED TO BE SWUNG UP AND DOWN IN A VERTICAL ARC, THE BOOM HAVING A PAIR OF CUTTER ARMS THEREON WHICH MAY BE SWUNG BACK AND FORTH ACROSS THE BOOM, ONE ARM BEING AT EACH SIDE OF THE LONGITUDINAL CENTER OF THE BOOM, EACH ARM HAVING A CUTTER HEAD AT THE OUTER END THEREOF EXTENDING BEYOND THE BOOM, AND CUTTER WHEELS ON EACH CUTTER HEAD ROTATABLE BY POWER MEANS, THE INVENTION COMPRISING A MECHANISM FOR SIMULTANEOUSLY MOVING THE CUTTER ARMS TOWARD AND AWAY FROM EACH OTHER AND THE LONGITUDINAL CENTER LINE OF THE BOOM, SAID MECHANISM COMPRISING: A SHAFT SUPPORTED ON THE BOOM BETWEEN THE TWO ARMS AND INTERMEDIATE THE ENDS OF THE BOOM, AN ECCENTRIC ARM-OPERATING MEANS ON THE SHAFT, A PAIR OF LINKS EACH HAVING ONE END OPERATIVELY ENGAGING SAID ECCENTRIC MEANS, ONE LINK OF SAID PAIR EXTENDING LATERALLY TOWARD ONE CUTTER ARM AND THE OTHER LINK EXTENDING LATERALLY TOWARD THE OTHER CUTTER ARM, THE OTHER ENDS OF SAID LINKS BEING PIVOTALLY CONNECTED TO THE RESPECTIVE CUTTER ARMS TOWARD WHICH THEY EXTEND AT A POINT INTERMEDIATE THE ENDS OF THE ARMS, AND A HORIZONTALLY-POSITIONED ELECTRIC MOTOR MOUNTED ON THE BOOM OPERATIVELY CONNECTED WITH SAID SHAFT FOR ROTATING IT, SAID MOTOR HAVING ITS TOP BELOW THE LEVEL OF THE TOP OF THE CUTTER WHEELS AND ITS BOTTOM ABOVE THE BOTTOM OF SAID CUTTER WHEELS, SAID MOTOR BEING OPERATIVE INDEPENDENTLY OF THE POWER MEANS FOR ROTATING THE CUTTER WHEELS AND VICE VERSA. 